What's in the night sky in the week of 6 to 12 March, 2023 in our weekly stargazing guide.


Chris Bramley Hello and welcome to Star Diary, the podcast from the makers of BBC Sky at Night Magazine. You can subscribe to the print edition of the magazine by visiting skyatnightmagazine.com or th digital edition by visiting on iTunes or Google Play.

Ezzy Pearson Greetings, listeners, and welcome to Star Diary, a weekly guide to the best things to see in the Northern Hemisphere's night sky. As we are based here in the UK, all times are in GMT. In this episode, we'll be covering the coming week from 6 to 12 March. I'm Ezzy Pearson, the magazine's features editor, and I'm joined once again by expert astrophotographer Charlotte Daniels. Thank you for joining us, Charlotte.

Charlotte Daniels Hi, it's lovely to be back.

Ezzy So, Charlotte, what have we got to look forward to this week?

Charlotte Now we're approaching that time of year where the days are just starting to draw out, which is nice in the sense that most of us are no longer heading off to work in darkness or coming home in the pitch black. However, it also means, of course, our nights are slowly getting shorter. Nevertheless, we're still lucky to have plenty of dark night sky opportunity as the Sun is rising in the UK about 6:30AM at the moment and setting a little before 6PM. So at least we have a few months before we lose astronomical darkness. But what is in store for the week 6 to 12 of March? Well, we have the Moon making its presence felt again as we're back at that stage in its cycle where it will be a Full Moon this week. So the Moon is 100% illuminated on Tuesday 7 March, and near enough to appear full throughout the week. So on 6 March it'll be about 99% illuminated. And by the end of the week, on Sunday 12th, it'll be 80% illuminated and in its waning phase. The thing about this week is that because it is this past the lunar cycle, our moon is up and high during most of our dark sky time, prime astronomy times are going to be dominated by the Moon. For example, at the start of the week on 6, it will be rising at 4:30PM and it won't set again until 7AM the next morning. These times do get later throughout the week as by Sunday it won't rise until 9:30PM. However, it is safe to say that this week our visual astronomy and astrophotography activities have to work around the Moon. Well, I say if the Moon is going to be out for so much of the week, let's embrace it. The days before and after Full Moon still provide opportunities for some lunar astronomy. This is because we have the terminator line casting shadows across some of the seas and craters. And while you won't see much detail when it's full, the days before and after can help you observe some of the outer craters. So as the Moon begins to wane at the end of this week, pop your telescope up to the Sea of Fertility and the Sea of Crises and to the outer edges of the Sea of Tranquillity. We'll see what additional details you can pick up as the shadows cast and can get depth and texture to the surface around these seas.

One thing that really helps a lunar observing session is a good filter, so lunar filters decrease light across visible wavelengths and they come in two main types. You have the neutral density filter, which is fixed, and you can buy with different transmission levels. So depending on how much light the filter will let through, it will darken the surface of the moon somewhat. And if is a particularly strong one, you may lose some detail. However, it'll stop a fully illuminated moon from dazzling you as it's super bright through a telescope eyepiece. Therefore, a neutral density filter can be a good choice around this full moon period. The other type of lunar filter is a polarising filter, which means you can actually alter the amount of light that passes through and means you can manually adjust according to how the moon is at the time of observation, which is my personal preference. Another thing we can try with the big bright moon is a bit of astrophotography. So during the week of 6-12 March, why not take out your DSLR and pop a lens on. Anything above 250mm will work very well. Or if you have a T-ring why not tag on to your telescope? In terms of camera settings, I always start by setting my camera to manual and the F-number to f7. I then set the quickest exposure time, which is about 1/4000 and the ISO pretty low, so between 100 and 300. The last thing I like to use is an intervalometer, which you plug into the side of the camera and will allow you to remote shutter release, which means you don't notice the camera when taking the image. You can then get an intervalometer for about £10-15 online and it's a really useful accessory for astrophotography. So pop your DSLR and lens on a tripod, use the intervalometer and see how these settings work for your DSLR. You can then play around by increasing the F-number to say 9 or 10 and perhaps increasing the ISO slightly. Or why not see what happens when you increase exposure time to the second shorter setting, which might be around 1/2000? Compare your test images and see which setting combination gives you the best results. For extra detail, why not try capturing multiple exposures so that you can stack them in a free stacking software such as AutoStakkert. You can then try popping your stacked image into RegiStacks and using the wavelet sharpening function to see what details you can extract. Another thing, if it's safe to do so and the sun has fully set, why not also try and take a picture of the Moon as it's rising and still close to the horizon? We tend to try and avoid capturing images before they reach a high altitude because we get more air turbulence and distortions closer to the horizon, which can reduce the quality of our images. However, I'm going to see if I can take an image of the rising Moon towards the end of this week. That's because pollutants in our atmosphere can affect the apparent colour of the Moon and the more evidence closer to the horizon. So you may notice in your image that the Moon will appear a little orange or red if you have a nice foreground, perhaps some trees. This can make a lovely and dramatic picture if you play around with the DSLR settings I mentioned earlier and lunar images are really easy to have a go at. And remember, if you're going to observe the moon, you may not actually need fully clear skies. So don't be put off if it's not crystal clear out there, a bit of patchy cloud or light haze is okay as this will actually help to stabilise the atmosphere and reduce the effects of seeing which can prevent us from resolving finer details. When we're looking at an object for deep sky objects, we need hours of crystal clear night to really take advantage. So that's another reason to embrace lunar astronomy this week so we don't have to be quite so at the mercy of the UK weather. So that's really what I'll be focusing on this week. I think I'll be turning my hand back to the Moon Astrophotography and I may even purchase myself a new lunar filter because I don't need much of an excuse to buy more astronomy equipment.

Ezzy It certainly does sound like it's going to be a great week to take a look at the moon. There'll be a full moon on 7 March, and even though the nights are getting a bit shorter, the Moon is going to be up nice and high in the sky throughout the week, giving you a great chance to catch up with our neighbour the Moon. Thank you very much for coming in to talk to us again today, Charlotte.

Charlotte Thanks, Ezzy. It was a real pleasure and I hope everyone enjoys their week looking at the Moon.

Ezzy And thank you very much. For those of you listening at home, if you'd like that, please do subscribe to the Star Diary podcast and we will hopefully see you back here next week for even more stargazing tips. If you want to find out even more spectacular sites that will be gracing the night sky throughout the month, be sure to pick up a copy of BBC Sky at Night magazine. Well, we have a 16 page pull out Sky Guide with a full overview of everything worth looking out for. Whether you like to look at the moon, the planets or the deep sky, whether you use binoculars, telescopes or neither. Our sky guide has got you covered with the detailed star charts to help you track your way across the night sky. From all of us here at BBC Sky and Night Magazine.


Chris Bramley Goodbye and thank you for listening to this episode of the START, our podcast from the makers of BBC Scotland magazine. For more of our podcasts, visit our website at www.skyatnightmagazine.com. Or head over to iTunes or Spotify.


Elizabeth Pearson
Ezzy PearsonScience journalist

Ezzy Pearson is the Features Editor of BBC Sky at Night Magazine. Her first book about the history of robotic planetary landers is out now from The History Press.